How a Demon can be summoned..I've answered this to my other answer at your post. There isn't "the best" or "the friendliest" Demon, neither "good" and "evil"... There isn't a "good" entity, or a "bad" entity... These are just words. Any entity has free will and acts how they desire..they're just words...

But I get your point. You should know very well what are you doing... For beginning, I suggest to summon/work with Paimon, Vassago or Valefor...

I find summoning to be a rude word. just imagine how the context from the would would sound if you use it on your deceased grandmother or dead friend. But if you want to "summon" a demon I would learn how to banish first. If you do not know how to banish something you called out, it could be a bad experience.

Also demons have lives and needs just like us and I wouldn't want to just bother one for the heck of it like some game. As for what you say what demon is best, I have no idea what you mean.